28 research outputs found
Non-convex approach to binary compressed sensing
We propose a new approach to the recovery of binary signals in compressed
sensing, based on the local minimization of a non-convex cost functional. The
desired signal is proved to be a local minimum of the functional under mild
conditions on the sensing matrix and on the number of measurements. We develop
a procedure to achieve the desired local minimum, and, finally, we propose
numerical experiments that show the improvement obtained by the proposed
approach with respect to the classical convex approach, i.e., Lasso
A Decoding Approach to Fault Tolerant Control of Linear Systems with Quantized Disturbance Input
The aim of this paper is to propose an alternative method to solve a Fault
Tolerant Control problem. The model is a linear system affected by a
disturbance term: this represents a large class of technological faulty
processes. The goal is to make the system able to tolerate the undesired
perturbation, i.e., to remove or at least reduce its negative effects; such a
task is performed in three steps: the detection of the fault, its
identification and the consequent process recovery. When the disturbance
function is known to be \emph{quantized} over a finite number of levels, the
detection can be successfully executed by a recursive \emph{decoding}
algorithm, arising from Information and Coding Theory and suitably adapted to
the control framework. This technique is analyzed and tested in a flight
control issue; both theoretical considerations and simulations are reported
Recovery of binary sparse signals from compressed linear measurements via polynomial optimization
The recovery of signals with finite-valued components from few linear
measurements is a problem with widespread applications and interesting
mathematical characteristics. In the compressed sensing framework, tailored
methods have been recently proposed to deal with the case of finite-valued
sparse signals. In this work, we focus on binary sparse signals and we propose
a novel formulation, based on polynomial optimization. This approach is
analyzed and compared to the state-of-the-art binary compressed sensing
methods
Non-convex approach to binary compressed sensing
We propose a new approach for the recovery of binary signals in compressed sensing, based on the local minimization of a non-convex cost functional. The desired signal is proved to be a local minimum of the functional under mild conditions on the sensing matrix and on the number of measurements. We develop a procedure to achieve the desired local minimum, and, finally, we propose numerical experiments that show the improvement obtained by the proposed approach with respect to classical convex methods
Online Optimization in Dynamic Environments: A Regret Analysis for Sparse Problems
Time-varying systems are a challenge in many scientific and engineering areas. Usually, estimation of time-varying parameters or signals must be performed online, which calls for the development of responsive online algorithms. In this paper, we consider this problem in the context of the sparse optimization; specifically, we consider the Elastic-net model. Following the rationale in [1], we propose a novel online algorithm and we theoretically prove that it is successful in terms of dynamic regret. We then show an application to recursive identification of time-varying autoregressive models, in the case when the number of parameters to be estimated is unknown. Numerical results show the practical efficiency of the proposed method